Response Organization in Attention Control and a Perceptual Serial Position Effect

Abstract

To determine the influence of response organization factors in selective attention, a comparison was made between the shadowing and monitoring techniques of attention control and a one-trial serial recall technique in which subjects were instructed to remember one message (attended channel) of a dichotic presentation. Detections of semantic targets in the attended and unattended messages from the remembering condition were quantitatively similar to those from the monitoring condition. This suggests that the low detection rates in the unattended message when subjects are shadowing are a function of the higher processing demands of overt response organization required by this task. A serial position effect was also in evidence: the detection probability was enhanced if the target was positioned towards either end of the serial presentation of 16 items. The primacy observed here, common to all three attention control conditions, indicates more efficient perceptual processing and subsequent categorizing of end items than of central, embedded items. The hypothesis is offered that the principles governing the present primacy effects may also underlie primacy in serial position curves of short-term memory studies.